Black363IROCZ

I was wondering if the 4.5L motors used in Cadillacs and GMs can use the same parts as a small block chevy motor?

Dave Y

nope, totally different
















some of the bolts might interchange, but thats it

dennis6

Go to www.fiero.nl if you want some info on the 4.5 caddies, alot of people putting them in Fieros and modding the engines the best they can without aftermarket support.

Black363IROCZ

thanks for the tips guys. my uncle has a 220 HP allante, wanted to see what we could do to bump it to 300 or so

Guest

The 4.5 caddy is not at all related to the 4.6 Northstar. Careful guys. The 4.5 is a derivative of the 4.1/4.9 caddy. Make sure you know exactly which it is first that you are working on.

dans82bird

hah, allante, I hate working on those pieces of crap.

Hellraiser

I'm doing a set of head gaskets on one of these right now (4.1 liter model). It's really no fun to work on, but not as complex a motor as some people would make it out to be. I can't imagine trying to tune one for performance, tho... these things are pretty much unique, sharing no parts with other gm engines that i can see... other than the caddy 4.5,4.9,etc.
I had been wondering what kind of a bellhousing bolt pattern it has tho, as the 305 tpi motor in my garage looks like it would be a nice fit under the hood.

dans82bird

hahaha, I just did head gaskets on a northstar.... crossthreaded like 3 head bolts in the pos... so HELL I timeserted all the head bolt threads... talk about a PITA!

Guest

Its the same bolt pattern as the FWD Northstar, whatever that is. Its not the same as the SBC setup, from what I understand.

Dave Y

the bellhousing bolt pattern of the northstar is the same as a 2.8 V6, so, best bet to use the engine in a RWDE car would be to have a 2.8 700R4 built w/V8 internals